1. Field of the Invention
The present invention relates to joint seals; and more particularly to a joint seal for sealing the space between adjacent architectural panels, such as window panels.
2. Description of the Related Art
In building design, it is often the architect's intention to incorporate an exterior window system that provides horizontal bands of windows with a minimum of apparent lines at the vertical joints between individual window panels so as to give the visual effect of an unbroken band of glass when viewed from the outside during daylight. This effect is heightened by using dark tinted glass or light reflecting glass.
With such systems, field labor constitutes a large part of the total window installation costs. Horizontal band or ribbon windows in widespread use are designed to be installed at least partially from outside of the building. When such windows are installed, temporary exterior fastener clips must be first manually inserted into the joints between individual window panels to support the window panels while interior window structural supporting adhesives cure. Once the interior window supporting adhesives are properly cured, the exterior temporary fasteners are manually removed and a sealing caulk is applied flush with the outside window panel surfaces along the exterior vertical spaces found at each window panel joint.
One such window joint assembly is illustrated in FIG. 1 and is referred to generally as 10. According to this prior art system, temporary glass retainer clips 11 are installed along the joints between individual window panels 12 and 13 when the window panels are initially set in place. A silicon adhesive 14 is then applied between each of the interior faces of the adjoining window panels and a window support member 15. The exterior temporary glass retainer clips 11 remains in place for a one to three week period during which time the silicon adhesive 14 undergoes a curing process. After the silicon adhesive 14 is fully cured, the external temporary glass retainer clips 11 are manually removed from the outside of each window joint and a polyurethane rod 16 is inserted into the opened vertical space. Next, a silicone caulk 17 is applied from the building exterior to fill in the remainder of each joint space flush with the window panel exteriors. Because the caulk 17 is manually applied to each joint, a uniform, pleasing external appearance is difficult to achieve. Once the interior silicon adhesive 14 is completely cured and the exterior silicon caulk 17 has been applied to the vertical window joint spaces to give the exterior of the band of windows an unbroken appearance, the window installation process is complete.
Although this window installation system achieves the desired effect of a continuous horizontal window band without obvious vertical joints, the installation process is extremely time consuming and labor intensive. For each joint between adjoining window panels, the temporary clips 11 may have to be applied from the exterior of the building to which glass is being applied, the polyurethane rod 16 must be inserted into the joint space from the building exterior one to three weeks after the clips 11 are applied, and the silicon caulk 17 must then be manually applied from the building exterior along the outside length of each joint between window panels.
Moreover, if a window installed as part of this type of system should break and have to be replaced, the broken window and the replacement window would have to be respectively removed and installed at least in part from the outside of the building in the same manner that the original window panel was installed and secured.
Window joint seals that do not require exterior installation are known for use in window systems that have specially formed window panels. One such window unit joint is disclosed in U.S. Pat. No. 4,464,874 to Shea, Jr. et al. wherein adjoining individual window panels are joined by compressing gasket members attached to the vertical edges of adjoining window panels. However, this window system arrangement may not be used in conjunction with standard manufactured insulating glass panels as it relies on a heavy spacer used in a minimum two-inch air space to provide support against wind load and to hold the edge seal gaskets. Further, this system requires an additional labor intensive manual caulking of the inside of each joint to provide an air seal.